A container or bin for storing phosphorous pentasulfide commonly includes a valve for opening and closing a fill/dispense port of the bin. This type of bin is often re-used many times to deliver multiple loads of phosphorous pentasulfide to the same or various customers. The valve is opened at the supplier to install phosphorous pentasulfide in the bin. After the valve is closed, the bin is delivered to the customer. The customer opens the valve to dispense the phosphorous pentasulfide as desired. If possible, the customer closes the valve, and returns the bin empty to the supplier. The bins and their valves are subject to harsh conditions due to the nature of the phosphorous pentasulfide, fluctuations in weather, and rough treatment by some personnel opening and closing the valves. Conventional valves do not last long in the field before requiring maintenance and/or repair. Phosphorous pentasulfide is generally hazardous and should be well contained. Valve malfunction and valve maintenance can subject workers to undesired exposure to phosphorous pentasulfide. Moreover, ingress of moisture through the valve is undesirable because phosphorous pentasulfide reacts with water to form hydrogen sulfide, sulfur dioxide, and phosphoric acid.